Lead (Pb) poisoning still remains a significant public health problem. Developmental exposure to Pb often results in abnormalities, most notably cognitive deficits in children and laboratory animals. Pb is a neurotoxicant with many sites of action in the central nervous system. The goal of this research is to determined if changes in serotonin receptors (5-HT2c) contribute to the conditions associated with Pb poisoning by Pb-induced perturbation to pregnant rats. To achieve this goal, animal models of Pb-exposed rats will be used to evaluate a number of pharmacological parameters. These parameters include, quantitation of serotonin levels by means of high performance liquid chromatography (HPLC), and radioligand binding assays. The finding may help understand a particular mechanism of Pb toxicity.